[BWentler]

My setup:

Table: VPI HW19 mkIV, w/ Super Acrylic armboard & the dust cover off
Tonearm: AudioQuest PT-9b (1.5grams w/ no anti-skat)
Cartridge: Grado Reference Sonata
Phono Cable: Straight Wire Maestro II, 1meter
Phono Stage: several (tubed & SS)

When I start an album playing, things sound good but as the album proceeds, the sound become more and more forward and distorted at the upper range.  This is with 90% of ablums i've played.  I have owned this setup for about a year and things have been pretty consistant.

Any suggestions?

[nathanm]

I get the same thing on some records.   What I wish I knew is where the distortion is coming from: are the grooves damaged from previous use? (on used vinyl)  Is the stylus unable to properly track the otherwise intact groove? What the heck causes that tracking distortion anyway?

You may want to check your anti-skate setting.  As the tonearm moves inward it generally wants to slam towards the center but the anti-skate pulls it back.  That's about my best idea.  Or maybe increase the tracking force.  Seems like no matter what I do to mine some peaks are just nasty.

I would love to try a tangential tracking arm as those are supposed to solve such issues, but why there aren't more of them is beyond me.  Harder to implement I suppose.

Vinyl does sound nice, but man it's tough love sometimes.  There are some serious distortion issues in that medium!

[mgalusha]

This is caused by tracking error. Tracking error increases as the radius of the groove decreases. When the record is cut the cutter head is perpendicular to the groove. With a standard tone arm this can only occur in two locations on the record.

Longer arms tend to reduce the tracking error because of the larger arc traced.

I strongly suggest getting a cartridge alignment system and adjusting your cartridge as accurately as possible. I use the DB Protractor and find it reasonably easy to use and very helpful. You can also use the free one made available by Steve Rochlin of enjoythemusic.com. It can be found here.

HTH,

Mike